From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH -V2 0/9] memcg: add HugeTLB resource tracking Date: Thu, 1 Mar 2012 14:40:29 -0800 Message-ID: <20120301144029.545a5589.akpm@linux-foundation.org> References: <1330593380-1361-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1330593380-1361-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, David Gibson On Thu, 1 Mar 2012 14:46:11 +0530 "Aneesh Kumar K.V" wrote: > This patchset implements a memory controller extension to control > HugeTLB allocations. It is similar to the existing hugetlb quota > support in that, the limit is enforced at mmap(2) time and not at > fault time. HugeTLB's quota mechanism limits the number of huge pages > that can allocated per superblock. > > For shared mappings we track the regions mapped by a task along with the > memcg. We keep the memory controller charged even after the task > that did mmap(2) exits. Uncharge happens during truncate. For Private > mappings we charge and uncharge from the current task cgroup. I haven't begin to get my head around this yet, but I'd like to draw your attention to https://lkml.org/lkml/2012/2/15/548. That fix has been hanging around for a while, but I haven't done anything with it yet because I don't like its additional blurring of the separation between hugetlb core code and hugetlbfs. I want to find time to sit down and see if the fix can be better architected but haven't got around to that yet. I expect that your patches will conflict at least mechanically with David's, which is not a big issue. But I wonder whether your patches will copy the same bug into other places, and whether you can think of a tidier way of addressing the bug which David is seeing? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757283Ab2CAWkc (ORCPT ); Thu, 1 Mar 2012 17:40:32 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:51301 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753979Ab2CAWkb (ORCPT ); Thu, 1 Mar 2012 17:40:31 -0500 Date: Thu, 1 Mar 2012 14:40:29 -0800 From: Andrew Morton To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, David Gibson Subject: Re: [PATCH -V2 0/9] memcg: add HugeTLB resource tracking Message-Id: <20120301144029.545a5589.akpm@linux-foundation.org> In-Reply-To: <1330593380-1361-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1330593380-1361-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 1 Mar 2012 14:46:11 +0530 "Aneesh Kumar K.V" wrote: > This patchset implements a memory controller extension to control > HugeTLB allocations. It is similar to the existing hugetlb quota > support in that, the limit is enforced at mmap(2) time and not at > fault time. HugeTLB's quota mechanism limits the number of huge pages > that can allocated per superblock. > > For shared mappings we track the regions mapped by a task along with the > memcg. We keep the memory controller charged even after the task > that did mmap(2) exits. Uncharge happens during truncate. For Private > mappings we charge and uncharge from the current task cgroup. I haven't begin to get my head around this yet, but I'd like to draw your attention to https://lkml.org/lkml/2012/2/15/548. That fix has been hanging around for a while, but I haven't done anything with it yet because I don't like its additional blurring of the separation between hugetlb core code and hugetlbfs. I want to find time to sit down and see if the fix can be better architected but haven't got around to that yet. I expect that your patches will conflict at least mechanically with David's, which is not a big issue. But I wonder whether your patches will copy the same bug into other places, and whether you can think of a tidier way of addressing the bug which David is seeing?